Imaging Following Shoulder Instability Surgery
Laura W. Bancroft, MD1,2

1Diagnostic Radiology, Florida Hospital, Orlando, FL, United States, 2Diagnostic Radiology, University of Central Florida College of Medicine, Orlando, FL, United States

Synopsis

Imaging following shoulder instability surgery depends on suspected pathology. Direct anatomic repair of labral tears may be perfomed in conjunction with capsular shift. There should be no separation of the labrocapsular complex and glenoid margin with intact labral repair. Overall accuracy of MR arthrography for detecting labral tears after prior instability repair is > 90%. Arthroscopic Bankart repair may be performed in conjunction with remplissage procedure in patients with engaging Hill-Sachs lesion. MRI will show reattachment of posterior structures into the defect, along with anchor embedded in the trough. Postoperative imaging of Laterjet procedure must assess incorporation of the bone block and any recurrent imaging features of instability.

Imaging following shoulder instability surgery depends on the suspected pathology and includes radiographs, magnetic resonance imaging (MRI) or MR arthrography, computed tomography (CT) and CT arthrography. Direct anatomic repair of labral tears usually occurs by suturing the anterior labrum and joint capsule, and the anterior band of the inferior band of the inferior glenohumeral ligament (IGHL) to the glenoid rim. Repairs may be perfomed in conjunction with a capsular shift procedure, with tightening of a capacious joint capsule. With MRI or MR arthrography, there should be no separation of the labrocapsular complex and glenoid margin with in intact labral repair. Capsular thickening with an irregular nodular contour is an expected postoperative finding of capsular repair. Comparison with prior MRI studies is of utmost importance to evaluate for retear. The overall accuracy of MR arthrography for detecting labral tears after prior instability repair varies in the literature, but is generally greater than 90%. Granulation tissue within a repaired labral tear may prevent joint fluid or contrast from outlining a persistent defect, resulting in a false negative MR examination. Arthroscopic Bankart repair after recurrent anterior shoulder dislocation may be performed in conjunction with the remplissage procedure in patients with an engaging Hill-Sachs lesion. The remplissage technique transfers the posterior capsule and infraspinatus tendon into the Hill-Sachs lesion in order to prevent engagement of the lesion on the glenoid rim. MRI will show reattachment of the posterior structures into the defect, along with the metallic or bioabsorbable anchor embedded in the trough. Postoperative imaging in patients with recurrent anterior shoulder instability may be helpful in those who have undergone procedures addressing a deficient anterior inferior glenoid. The Latarjet (also known as Laterjet-Bristow) procedure involves transfer of the tip of the coracoid process along with the conjoined tendon through a horizontal slit in the subscapularis to the anteroinferior glenoid neck. The transferred short head of the biceps and coracobrachialis serve as a dynamic buttress across the anteroinferior glenohumeral joint when the shoulder is abducted and externally rotated. Postoperative imaging of the Laterjet procedure (and modifications of this technique) is aimed at assessing incorporation of the bone block and any recurrent imaging features of instability.

Acknowledgements

No acknowledgement found.

References

1. Jacobson JA, Miller B, Bedi A, Morag Y. Imaging of the postoperative shoulder. Semin Musculoskelet Radiol 2011;15:320-339.

2. Sugimoto H, Suzuki K, Mihara K, Kubota H, Tsutsu H. MR arthrography of shoulder after suture-anchor Bankart repair. Radiology 2002;224:105-11.

3. Probyn LJ, White LM, Salonen DC, Tomlinson G, Boynton EL. Recurrent symptoms after shoulder instability repair: Direct MR arthrographic assessment – correlation with second-look surgical evaluation. Radiology 2007;245:814-23.

4. Zhu YM, Lu Y, Zhang J, Shen JW, Jiang CY. Arthroscopic Bankart repair combined with remplissage technique for the treatment of anterior shoulder instability with engaging Hill-Sachs lesion: A report of 49 cases with a minimum of 2-year follow-up. Am J Sports Med 2011;39:1640-7.

5. Garcia GH, Wu HH, Liu JN, et al. Outcomes of the Remplissage procedure and its effects on return to sports: Average 5-Year follow-up. Am J Sports Med. 2016 Feb 17.Epub ahead of print.

6. Bohu Y, Klouche S, Gerometta A, et al. Outpatient Latarjet surgery for gleno-humeral instability: Prospective comparative assessment of feasibility and safety. Orthop Traumatol Surg Res. 2016 Mar 1.Epub ahead of print.

7. Anderl W, Pauzenberger L, Laky B, et al. Arthroscopic implant-free bone grafting for shoulder instability with glenoid bone loss: Clinical and radiological outcome at a minimum 2-year follow-up. Am J Sports Med. 2016 Feb 10. Epub ahead of print.

Figures

Fig. 1. Intact superior labral repair. Coronal oblique proton density image demonstrates intact, reattached superior labrum (arrowhead) and intact superior labral anchor (arrow).

Fig. 2. Anterior and posterior labral retear in 21-year-old man. (A and B) Coronal oblique T1-sat suppressed (A) and axial proton density fat suppressed (B) images from MR arthrogram demonstrate irregular contrast extension into the superior and posterior labrum (arrows), consistent with retear. Suture anchors (arrowheads) remained well seated.

Fig. 3. Laterjet procedure in 22-year-old woman with recurrent anterior shoulder dislocation. Anteroposterior radiograph of the right shoulder shows immediate postoperative change after Laterjet procedure, with transfer of the coracoid process (arrowheads) into the deficient anterior inferior glenoid.

Fig. 4. Modified Bristow procedure, capsular shift and labral repair in 56-year-old man. (A and B) Axial (A) and sagittal (B) MR arthrographic images demonstrate remote postsurgical changes after modified Bristow procedure, capsular shift and labral repair. Note the remodeling of the reconstructed anterior inferior glenoid (arrowheads) after incorporation of transferred coracoid process and susceptibility artifact along the anterior glenoid (arrow) from the capsular shift and labral repair.



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)